This application seeks five years continued funding for a training program in Basic Microbiology and Infectious Diseases (BMID) to support six predoctoral trainees and three postdoctoral trainees with the aim of producing independent investigators capable of sustaining productive research programs studying the molecular mechanisms of infectious disease. The program has been active for 20 years. The program comprises of 16 faculty preceptors from 5 departments (Molecular Genetics & Microbiology, Biochemistry & Molecular Biology, Pediatrics, Medicine and Pathology, Immunology & Laboratory Medicine) within the College of Medicine in the Health Science Center at the University of Florida in Gainesville. The program faculty include bacteriologists (Gulig, Jin, Southwick, Rosenzweig), virologists (Bloom, Byrne, Chang, Condit, Flanegan, Flotte, Goodenow, R. Moyer, S. Moyer, Muzyczka, Swaminathan), and mycologists (Lewin, Rosenzweig). The program faculty have expertise in genetics, cell biology, pathogenesis, immunology, and molecular Biology. The program faculty also includes clinician scientists (Flotte, Byrne, Southwick, Swaminathan), thus reinforcing the clinical relevance of microbiology and infectious disease. Predoctoral trainees are recruited and initially trained in collaboration with the College of Medicine's Interdisciplinary Program in Biomedical Sciences (IDP). The pool of trainee candidates averages 40 per year, they come from throughout the US, and they average combined verbal and quantitative GRE scores of 1250 and GPA's of 3.5. The IDP provides comprehensive classroom training, an introductory laboratory, laboratory rotations, and advanced course work in specialized disciplines. Subsequent training focuses on independent laboratory research supplemented with program-specific activities stressing communication skills. Predoctoral training requires a total of approximately 5 years, including a first year of support from the College of Medicine, an average of 2 years of support from the training grant and the remainder of support from the mentor's research grant or other external sources. Postdoctoral trainees are recruited nationally both at the Ph.D. (90%) and M.D. (10%) level. Training for postdocs focuses almost exclusively on laboratory research, supplemented with seminars and journal clubs. Postdoctoral training requires 3-4 years, with an average of two years of support from the training grant and the remainder of support from the mentor's research grant or other external sources.